Centrifugal superchargers are one of the most popular power adders to bolt onto a street car or race car to crank up the horsepower levels. These superchargers have not only grown in popularity as their development and subsequent capabilities have increased, but they’ve also grown in size to make them a viable option for the quickest and fastest classes in drag racing. Today, we’re going to look at ProCharger’s lineup of F-4X superchargers and learn about what makes them such impressive pieces of boosted technology.
To set the stage for what we’re going to cover, let’s do a quick refresher course on how a centrifugal supercharger works. A supercharger case is fitted with gears that are used to turn the impeller and move air through the unit. The ratio of these gears dictates how fast the supercharger will spin. The ratio can be tuned to match the supercharger’s performance envelope to the engine’s.
The F-4X Series Of Superchargers Explained
If you were going to create a roadmap of the upgrade path for ProCharger’s superchargers, the F-4X series would be the final stop. These units were developed to be the next evolution of ProCharger’s product line from the F-3 series, to quench the horsepower thirst of those trying to go as quick and fast as possible.
The F-4X series of superchargers were created using a clean slate and went through a rigorous testing process. ProCharger engineers collaborated with racers to optimize the final product so it could work in the high-horsepower classes of the drag racing world. This was done to ensure that the racer’s needs would be met.
Cliff Hall, engineering director at ProCharger, talks about the development process for the F-4X superchargers.
“Understanding what and how the F-4X came about is core to understanding the success of these three products in the F-4 lineup. The F-4X concept evolved from years of experience with past ProCharger models. The design began as a 3D model, went through simulation, and then prototyping. Engine builders, race teams, and ProCharger engineers were all involved in the lab testing, dyno testing, and track testing to fine-tune the design and launch this product.”
ProCharger didn’t want to require its customers to make wholesale changes to their race cars when they upgraded from an F-3X supercharger to the F-4X. This goal was achieved by engineering the F-4X to be compatible with any of the gear drive units that are currently available for the F-3X. Since the F-4X was designed this way, racers typically have to make minimal modifications to get the blower to fit in place of an F-3X unit.
The F-4X concept evolved from years of experience with past ProCharger models. – Cliff Hall, ProCharger.
What sets the F-4X apart from previous superchargers offered by ProCharger is its gear case. ProCharger wanted to increase the F-4X’s durability, so it made the unit’s gear case thicker. This redesigned case is .3-inches deeper to accommodate the helical-cut gears that ProCharger added to the F-4X. Helical-cut gears are used inside the gear case to help shift the large loads generated by the supercharger. The increased durability provided by the F4-X is a requirement since it was designed to be used in classes like Pro Modified, Pro 275, and no-prep racing, where racers really push parts to their limits.
The internal step-up gear ratio of the F-4X was changed to 4.77:1 compared to the F-3X’s 5.63:1; this ratio change opened up a new world of drive ratios that racers can run inside their supercharger crank drives. That means racers now have even more ways to manipulate the power output of the supercharger, and also have another tuning tool at their disposal.
Three Brothers: The F-4X-140, F-4X-140-1, and F-4X-144
ProCharger has found a way to get a lot of mileage out of its new F-4X supercharger design. To take advantage of the F-4X platform, ProCharger now offers three different variants of the supercharger: the F-4X-140, F-4X-140-1, and F-4X-144. These superchargers are capable of generating anywhere from 3,500 to 4,000 horsepower.
Let’s take a look at each of these superchargers, their specifications, and the racing categories they’re geared toward (no pun intended).
First is the F-4X-140. This supercharger’s inducer measures 5.47-inches and sucks air in through a 13.5-inch volute. On the backside of the supercharger you’ll find a 7.22-inch exducer. The F-4X-140’s max flow is a healthy 4,500 cfm, and it can produce up to 60 psi of boost. When you put all of that together you get a supercharger that’s capable of cranking out 3,500 horsepower.
“The F-4X-140 is the spec-model centrifugal supercharger for the NHRA Pro Mod class. This supercharger is perfect for classes that need durability and reliability for 1/4-mile drag racing. Racers can really get a lot out of this supercharger by optimizing the blower speed to get the maximum amount of horsepower possible,” Hall says.
The main difference between the 140, 140-1, and 144 is the inducer diameter (compressor wheel), which affects the overall boost/airflow capacity and performance. – Cliff Hall.
If you’re a racer that isn’t locked into using a spec supercharger and need some additional horsepower, the F-4X-140-1 is the supercharger for you. The F-4X-140-1 features a larger 5.51-inch inducer. A 7.42-inch exducer diameter can be found on the rear of the compressor wheel of the F-4X-140-1. That additional .04 inches of inducer diameter and and .20 inches of exducer diameter helps the F-4X-140-1 move 4,700 cfm of air, or 200 cfm more than the F-4X-140. That additional air allows the F-4X-140-1 generate more than 3,700 horsepower and 65 psi of boost.
“If you’re running a class that allows you to use a true 140mm inducer, the F-4X-140-1 is the supercharger to use. This unit can support upwards of 3,700 horsepower, so it’s a great fit for people who compete in the Midwest Drag Racing Series, PDRA Pro Boost, No Prep Kings, different radial classes, and outlaw Pro Mod series,” Hall explains.
Now, let’s say you’re not hamstrung by supercharger size restrictions and need to make enough horsepower to rotate the Earth. In this situation, the F-4X-144 is going to be the right fit. The F-4X-144 uses an impeller with a 5.63-inch inducer and 7.91-inch exducer — the largest offered by ProCharger. When it comes to airflow, the F-4X-144 can move an impressive 5,000 cfm of air, and at full song can produce over 4,000 horsepower and 70 psi of boost.
“The F-4X-144 is for classes where the 140mm inducer rule isn’t used. Racers who are trying to make close to 4,000 horsepower are the ones who will use this supercharger. This unit needs the right blower speed to make the most horsepower on a Hemi application. Our large motorsports team can help racers optimize this supercharger to their engine package,” Hall states.
Long gone are the days when centrifugal superchargers were suited to street cars and lesser-powered outlaw race cars. ProCharger has put significant effort and resources into developing the F-4X line of centrifugal superchargers, and the results on the racetrack speak for themselves. Each of these units is capable of making incredible levels of horsepower for use in a variety of the quickest, fastest, and most elite categories. And they’ve done so with an array of world records, race victories, and championships.